Slingshot Harness

by Number One Laboratories


The Slingshot Harness is made of strong elastic bands. It is designed specifically for use with Number One Laboratories STPs. This includes:

The Number One STP, The Sport STP, Model E STP

It may be possible to use this harness with other STPs and soft packers, however, we cannot guarantee that it will not damage your prosthetic. 


Use a measuring tape to measure the circumference around your thigh. Or use a ruler to measure the leg-hole in a pair of well-fitting briefs. 

XS: 14"-17" / 35cm-40cm

Small: 17"-20" / 40cm-50cm

Medium: 20"-24" / 50cm-60cm

Large: 24"-28" / 60cm-70cm

XL: 28"-32" / 70cm-80cm

Customer Reviews

Based on 22 reviews
Pier Franzen
Feels like wearing nothing at all!

Feels like wearing nothing but holds things in place! I’m a big fan.

Chris Ellis

Slingshot Harness

Caiden Coleman
I love it

I had two orders delivery was long but i love everything

Angel Newsome

The slingshot works well but I’m excited to try the new one they just came out with that I bought!

Merutsuki Inuyoukai

Slingshot Harness


Your order will typically ship within 2-3 business days after purchase.

**Our Warehouse is moving which may cause an extra 3-4 days delay in fulfillment and delivery times until the end of August.

Please note that print-to-order apparel items, such as t-shirts, hoodies, etc... require additional processing time and will be shipped separately.


STP, Packer, Harness, Swimwear and Underwear sales are final. They cannot be exchanged or returned due to legal restrictions. Please consult size charts carefully; Sizes vary between brands. It's recommended to get accurate measurements taken by a pal. All other returns are issued as in-store credit only.

International Orders

Please note that for all non-US orders, you may be charged local taxes to retrieve your order.

Additionally, all international sales are considered final. See our Shipping Policies for more details.