Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 1
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 2
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 3
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 1
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 2
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 3
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 1
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 2
Uni-Ball UMN155-07 Signo RT1 Retractable Gel Pen Fine 0.7mm Blue Black - image 3
Uniball

Uni-ball Signo RT1 UMN155-07 Retractable Gel Ink Rollerball Pen 0.7mm Blue Black

Regular price
$27.02
Sale price
$27.02
Regular price
RRP $28.49
Or 4 payments of $6.76 with
Add items to a quote for bulk pricing, approvals, or purchase orders.

SKU: UMUMN155-07BB

UPC: 4902778269992

MPN: UMN155-07BB

The Darker Blue, Blue Black

Blue black is the darker of the two blues in this range, and this is the blue black version of uni-ball's UMN155-07 code.

One thing to know about the code. uni-ball publishes UMN-155 as the group and lists this pen as UMN155-07 on its product page, while the same pen appears in the catalogue with hyphens placed differently. The sibling ultra fine code is written UMN155-038 in one place and UMN-155-38 in the other. It is inconsistent at uni-ball's end, not ours, so searching either spelling should find the same pen.

Blue black sits close enough to black to look deliberate on a formal document while still being obviously not black next to one. That makes it useful where a signature or an annotation needs to be identifiable as original. The retractable barrel, which uni-ball states for this model, keeps it ready without a cap.

Plain black and plain blue in this width are at gel pens, as are the narrower Signo RT1 codes. The rest of the brand is at uni-ball, other types at pens, and the desk list at writing supplies.

  • Blue black gel ink, dark enough for formal use and clearly not plain black
  • Retractable mechanism, stated by uni-ball for this model
  • Gel ink, which uni-ball describes as new improved gel ink
  • 0.7mm line width, taken from uni-ball's 2026 product catalogue rather than the product page
  • Rubberised barrel grip, as described on uni-ball's product page
  • One of three Signo RT1 widths uni-ball lists under the UMN-155 code group
  • Formal documents, deeds and letters where a dark ink is expected
  • Signatures and annotations that need to read as original rather than copied
  • Everyday writing for anyone who finds plain black flat
  • Desk use alongside plain black and plain blue in the same width

Shipping

Shipping is kept simple with flat rates for selected areas and free shipping where applicable. Large, bulky, rural or out-of-area orders may require additional freight, and our team will contact you if this applies. For a more specific estimate, simply add this product to a quote or visit our shipping page.

Delivery Times

Melbourne, Sydney, Brisbane, Adelaide — 1 to 3 business days
Perth — 1 to 5 business days
Regional & Outer Areas — 3 to 7 business days

Returns

If you have questions about returns, please contact us or visit our returns page for full details.

Specifications

Brand: uni-ball

Range: Signo RT1

Manufacturer Code: UMN155-07

Manufacturer Code Group: UMN-155

Mega Code: UMUMN155-07BB

Colour: Blue Black (the store's own name for this variant)

Line Width: 0.7mm (published in uni-ball's 2026 product catalogue, not on the product page)

Ink Type: Gel ink

Mechanism: Retractable

Grip: Rubberised barrel grip, as described on uni-ball's product page

Pack: Not confirmed for this SKU; under review

Barcode: 4902778269992

Country Of Origin: Not published by the manufacturer

FAQs

uni-ball's product page for the Signo RT1 does not publish a tip size at all, only the description 'Ultra fine retractable rollerball pen for precision writing'. The 0.7mm belongs to uni-ball's 2026 product catalogue, and that is where we have taken it from. We would rather say so than imply the product page carries it.
uni-ball does not publish a refill code for UMN155-07, so we are not going to name one. We do stock Signo retractable refills as separate items, but matching one to this pen is worth confirming against the pen in hand before ordering in quantity.
Yes. uni-ball states the retractable mechanism for this model on its own product page. That is not true of every pen in the Signo family, so it is worth saying plainly for this one rather than assuming it across the range.
We are not stating a count for this SKU. uni-ball publishes no pack size for UMN155-07, and our own records for these eight inks contradict each other, so rather than guess we have left it off the listing and flagged it for review. Ask us before ordering if the count matters to you.
No. uni-ball publishes no colour names as text for the Signo RT1 range, only a gallery of images. Blue Black is the store's own name for this variant. The code and the barcode are the identifiers that will match a supplier's records.
uni-ball lists three codes under UMN-155: UMN155-07, UMN155-05 and UMN155-038. The catalogue puts them at 0.7mm, 0.5mm and 0.38mm. This is the widest of the three, so it lays the most ink; the narrower two suit smaller handwriting and tighter forms.

Shipping & Delivery

Delivery time depends on your location, the size of your order, and the shipping option selected at checkout. For in-stock items, standard metro delivery in QLD, NSW and VIC is usually 1 to 7 business days. South Australia, Tasmania, Western Australia and the Northern Territory are generally 3 to 12 business days. Express delivery for eligible parcels under 3kg is usually 1 to 4 business days in QLD, NSW, ACT and VIC. Delivery estimates apply to in-stock items only and may vary due to carrier conditions or delays.

If you need to make a change to your order, please contact our team as soon as possible. Once an order has been processed or dispatched, changes may no longer be possible. You can contact us through our Contact Us page for assistance.

Mega Office Supplies ships orders Australia wide and occasionally internationally. The best avenue would be to contact us so we can customise a specific quote for you. Please note that associated international duties, taxes and levies will be the responsibility of the customer.

Returns, Refunds & Replacements

Mega Office Supplies accepts change-of-mind returns for unopened and unused products within 14 days from the invoice date, provided the item is returned in its original packaging and in resalable condition. Original shipping costs are not refundable, return shipping is the customer’s responsibility, and a restocking fee may apply depending on the product type and supplier. Some items, including electronics, assembled or installed furniture, food, beverages, medicines, custom-made products, and certain bulk or special-order items, are not eligible for return unless required under Australian Consumer Law.

If your order arrives faulty, damaged, or incorrect, please contact Mega Office Supplies as soon as possible. Where required under Australian Consumer Law, a repair, replacement, or refund will be offered. In these cases, Mega Office Supplies will cover reasonable return shipping costs, and photographic evidence may be requested to help process the claim. Items should be reported within a reasonable timeframe after delivery.