For an inexpensive, lightweight and small trauma kit, I strongly recommend the "Patrol Officer's Pocket Trauma Kit" from Rescue Essentials (order either from http://www.rescue-essentials.com/ or from Amazon, especially if you're a Prime member). It's far from complete and it's not what I carry on the range, but for the price point it can't be beat.

It contains a SWAT-T tourniquet, Z-Pack Dressing, a pair of gloves, and three feet of duct tape. If you have a sharp with you, the plastic bag containing it can be used with the duct tape to create a field-expedient chest seal.

The SWAT-T isn't the best tourniquet out there -- I'd hate to be applying it to my own arm -- but it's inexpensive, easy to use, and can double as a pressure dressing with the Z-Pack. The preferred tourniquets (CAT-T, SOFTT-W) are far more expensive.

I have no connection to Rescue Essentials or Amazon other than as a customer.