BD Ultra-Fine™ 6mm x 31G insulin syringe, 25% shorter than the 8mm needle. This length is supported by recent recommendations published in Mayo Clinic Proceedings that advocate using the shortest needle first-line for all patient categories.1† Preferred by most patients over their current needle length, BD Ultra-Fine™ 6mm x 31G insulin syringes provide approximately 3x-lower risk of intramuscular injection compared to a 8-mm needle.